Method, device, storage medium and electronic equipment for producing undercut filling of tooth model

Abstract

The present application relates to a method, device, storage medium, and electronic device for producing undercuts in a tooth model, wherein the method comprises: determining whether adjacent teeth in a three-dimensional tooth model have moved tooth positions, and obtaining a determination result; determining the mesial control point and the distal control point between the adjacent teeth based on the determination result; generating a corresponding undercut model based on the mesial control point and the distal control point; and filling the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance. The target tooth model is obtained by filling the undercut model into the corresponding undercut in the three-dimensional tooth model, and the target tooth model is 3D printed into a physical object, in which the undercut has been filled, so that the orthodontic appliance formed by pressing the physical object will not get stuck in the undercut, thereby making it easier for people to remove the orthodontic appliance.

Description

Technical Field

[0001] The present application relates to the field of computer application technology, and in particular to a method, device, storage medium and electronic device for producing undercut filling in tooth models. Background Art

[0002] With the development of science and technology, 3D modeling technology is increasingly being used in dental medicine, playing an important role in various fields of dentistry, such as dental restoration, orthodontics, oral medicine, and oral surgery. Constructing 3D models helps researchers understand and grasp the external morphology and internal structure of teeth, making it easier to create 3D tooth models.

[0003] In the related art, a three-dimensional tooth model is obtained through three-dimensional modeling technology, 3D printing is performed based on the three-dimensional tooth model to obtain a physical object, and the orthodontic appliance is pressed and formed according to the physical object of the three-dimensional tooth model, so that the orthodontic appliance is finally more closely matched with the teeth.

[0004] Because the crown of the tooth is wider than the root, there is an undercut between adjacent teeth that is wider at the top and narrower at the bottom. If the braces made based on the three-dimensional tooth model are worn directly, the braces will get stuck in the undercut and cannot be removed smoothly, making it inconvenient for people to remove the braces. Summary of the Invention

[0005] In order to facilitate personnel to remove the braces, the present application provides a method, device, storage medium and electronic equipment for producing undercut filling in tooth models.

[0006] In a first aspect of the present application, a method for producing an undercut filling in a tooth model is provided, specifically comprising:

[0007] Determine whether there is a tooth position shift among adjacent teeth in the three-dimensional tooth model and obtain a determination result;

[0008] Determining a mesial control point and a distal control point between adjacent teeth according to the judgment result;

[0009] generating a corresponding undercut model according to the mesial control point and the distal control point;

[0010] The undercut model is filled into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance.

[0011] By adopting the above technical solution, based on the result of determining whether the adjacent teeth have moved or not, the mesial and distal control points of the undercut between the adjacent teeth are determined. The mesial and distal control points are used to better describe the shape of the undercut between the adjacent teeth. Then, based on the surface generation algorithm, an undercut model is generated based on the determined mesial and distal control points. Finally, the undercut model is filled into the corresponding undercut in the three-dimensional tooth model to obtain the target tooth model. The target tooth model is then 3D printed into a physical object with the undercut already filled. This prevents the braces formed by die-casting from the physical object from getting stuck in the undercut, making it easier for people to remove the braces.

[0012] Optionally, the mesial control point and distal control point of adjacent teeth are determined based on the judgment result, including: when the judgment result is that the adjacent teeth have moved tooth positions, selecting the first mesial control point between the adjacent teeth, the first mesial control point including the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point, the first mandibular buccal point is located at the buccal 1 / 3 of the mesial marginal ridge, the first mandibular lingual point is located at the lingual 1 / 3 of the mesial marginal ridge, the first gingival buccal point is located at the projection of the first mandibular buccal point along the long axis of the tooth to the gingiva, and the first gingival lingual point is located at the projection of the first mandibular lingual point along the long axis of the tooth to the gingiva; selecting a first distal control point symmetrical to the first mesial control point, and using the first mesial control point as the mesial control point, and using the first distal control point as the distal control point.

[0013] By adopting the above technical solution, if there is a movement of tooth positions of adjacent teeth, four position points on the adjacent teeth, namely the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point, are selected as the first mesial control point, and the first distal control point is symmetrical to the first mesial control point. Among them, the first distal control point and the first mesial control point are selected at one-third of the distance from the mesial marginal ridge, which can enable the orthodontic appliance to better utilize the surface of the tooth extension gap, increase the release area between the orthodontic appliance and the teeth, and thus better prevent the orthodontic appliance from falling off.

[0014] Optionally, the determining of the mesial control point and distal control point of the adjacent teeth according to the judgment result includes: when the judgment result is that there is no tooth position movement of the adjacent teeth, selecting the second mesial control point between the adjacent teeth, the second mesial control point including the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point and the second gingival lingual point, the second mandibular buccal point is located at the intersection of the mesial buccal cusp extending toward the mesial proximal surface and the adjacent surface, the second mandibular lingual point is located at the intersection of the mesial lingual cusp extending toward the mesial proximal surface and the adjacent surface, the second gingival buccal point is located at the mesial 1 / 3 of the midpoint of the buccal cervical margin line, and the second gingival lingual point is located at the mesial 1 / 3 of the midpoint of the lingual cervical margin line;

[0015] A second distal control point symmetrical to the second mesial control point is selected, and the second mesial control point is used as the mesial control point, and the second distal control point is used as the distal control point.

[0016] By adopting the above technical solution, if there is no movement of the adjacent teeth, four position points on the adjacent teeth, namely the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point and the second gingival lingual point, are selected as the second mesial control point, and the second distal control point is symmetrical to the second mesial control point, wherein the second mandibular buccal point and the second mandibular lingual point are selected at the intersection of the mesial proximal surface extension and the proximal surface, and the second gingival buccal point and the second gingival lingual point are selected at the mesial third of the midpoint of the buccal and lingual cervical margin line, so that the outward gap between the adjacent teeth can also be filled, thereby reducing the concave of the adjacent teeth and facilitating better dislocation of the orthodontic appliance.

[0017] Optionally, generating a corresponding undercut model according to the mesial control point and the distal control point includes:

[0018] generating a mesial closed curve according to the mesial control point;

[0019] generating a distal closed curve according to the distal control point;

[0020] Based on a ruled surface generation algorithm, an undercut surface is generated through the mesial closed curve and the distal closed curve, and the undercut surface is closed to obtain a corresponding undercut model.

[0021] By adopting the above technical solution, the selected mesial control points are used to generate a mesial closed curve according to the algorithm, and the selected distal control points are used to generate a distal closed curve according to the algorithm. Finally, based on the distal closed curve and the mesial closed curve, the ruled surface generation algorithm is used to generate an undercut surface, and the mesial and distal sides of the undercut surface are closed respectively, so as to obtain a complete undercut model surface mesh, and then obtain an undercut model of the undercut between adjacent teeth.

[0022] Optionally, generating a mesial closed curve according to the mesial control point includes:

[0023] The mesial control point is used to generate a mesial closed curve through a cubic B-spline curve interpolation algorithm; and a distal closed curve is generated according to the second distal control point;

[0024] Generating a distal closed curve according to the distal control point includes:

[0025] The distal control point is interpolated using a cubic B-spline curve algorithm to generate a distal closed curve.

[0026] By adopting the above technical solution, a cubic B-spline curve interpolation algorithm is used to generate a mesial closed curve according to the mesial control point and a distal closed curve according to the distal control point. Compared with piecewise linear interpolation, B-spline is differentiable at the nodes and has the advantage of smoothness, so that a closed curve with a smaller error can be fitted according to the algorithm. In addition, the shape of the closed curve can be changed by changing the control points.

[0027] Optionally, the three-dimensional tooth model includes initial tooth posture information, and the step of determining whether adjacent teeth in the three-dimensional tooth model have moved tooth positions to obtain a determination result includes:

[0028] Calculating the initial tooth position information and the preset target tooth position information to obtain the rotation amount and translation amount of the tooth; if the rotation amount and the translation amount are both zero, it is determined that there is no tooth position movement of the adjacent teeth;

[0029] If the rotation amount and the translation amount are not both zero, the judgment result is that the tooth position of the adjacent teeth is moved.

[0030] By adopting the above technical solution, the initial tooth posture information and the target tooth posture information are subjected to matrix operation, and the relative change of the tooth equivalent to the target tooth posture can be obtained, and the rotation and translation of the tooth can be obtained. If the rotation and translation are both zero, the tooth has not undergone angular rotation and position shift, indicating that the adjacent teeth have not moved at this time; if as long as one of the rotation and translation is not zero, the tooth has undergone angular rotation or position shift, indicating that the adjacent teeth have moved at this time, thereby more accurately judging the movement of the adjacent teeth.

[0031] Optionally, the step of determining whether adjacent teeth in the three-dimensional tooth model have moved tooth positions, before obtaining the determination result, further includes:

[0032] Obtain a 3D tooth model.

[0033] By adopting the above technical solution, the data of the three-dimensional model of a person's teeth is obtained through a dental three-dimensional scanner, and then a three-dimensional model of the teeth is generated based on the data of the three-dimensional model of the teeth, thereby improving the visualization of the teeth and making it easier for people to understand the internal structure of the teeth.

[0034] In a second aspect of the present application, a device for filling undercuts in tooth models is provided, specifically comprising:

[0035] a tooth movement judgment module, configured to judge whether adjacent teeth in a three-dimensional tooth model have moved tooth positions and obtain a judgment result; a control point determination module, configured to determine a mesial control point and a distal control point between adjacent teeth based on the judgment result; and an undercut model generation module, configured to generate a corresponding undercut model based on the mesial control point and the distal control point;

[0036] The undercut filling module is used to fill the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model to make an orthodontic appliance. By adopting the above technical solution, the tooth movement judgment module determines whether there is a moved tooth position according to the three-dimensional tooth model, and the control point determination module determines the mesial control point and distal control point of the undercut between adjacent teeth according to the judgment result obtained by the tooth movement judgment module. Then the undercut model generation module generates the undercut model between adjacent teeth according to the mesial control point and the distal control point. Finally, the undercut filling module fills the generated undercut model into the undercut of the three-dimensional tooth model to obtain the target tooth model, so that the orthodontic appliance formed by 3D printing of the target tooth model will not be stuck in the undercut, which facilitates the removal of the orthodontic appliance.

[0037] In summary, this application includes at least one of the following beneficial technical effects:

[0038] 1. Based on the judgment result of whether the adjacent teeth have moved or not, the mesial and distal control points of the undercut between the adjacent teeth are determined. The mesial and distal control points are used to better describe the shape of the undercut between the adjacent teeth. Then, based on the surface generation algorithm, an undercut model is generated according to the determined mesial and distal control points. Finally, the undercut model is filled into the corresponding undercut in the three-dimensional tooth model to obtain the target tooth model. This ensures that the dental appliance molded according to the target tooth model will not get stuck in the undercut, making it easier for personnel to remove the appliance.

[0039] 2. Generate a mesial closed curve for each selected mesial control point according to the algorithm, and generate a distal closed curve for each selected distal control point according to the algorithm. Finally, generate an undercut surface based on the distal closed curve and the mesial closed curve using the ruled surface generation algorithm. The mesial and distal sides of the undercut surface are closed separately to obtain a complete undercut model surface mesh, and then obtain an undercut model of the undercut between adjacent teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 1 is a flow chart of a method for producing an undercut filling in a tooth model provided in an embodiment of the present application;

[0041] Figure 2 This is a schematic diagram of selecting a mesial control point and a distal control point provided in an embodiment of the present application;

[0042] Figure 3 1 is a flow chart of another method for producing undercut filling of a tooth model provided in an embodiment of the present application;

[0043] Figure 4 This is another schematic diagram of selecting a mesial control point and a distal control point provided in an embodiment of the present application;

[0044] Figure 5 Schematic diagram of the structure of an undercut model provided in an embodiment of the present application;

[0045] Figure 6 This is a schematic structural diagram of a device for producing undercut filling in a tooth model provided in an embodiment of the present application;

[0046] Figure 7 It is a structural schematic diagram of another device for producing undercut filling of tooth models provided in an embodiment of the present application.

[0047] Explanation of the accompanying reference numerals: 11. Tooth movement judgment module; 12. Control point determination module; 13. Undercut model generation module; 14. Undercut filling module. DETAILED DESCRIPTION

[0048] In order to enable people skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0049] In the description of the embodiments of this application, words such as "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0050] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. In addition, unless otherwise specified, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0051] See also Figure 1 The present application discloses a flowchart of a method for filling undercuts in tooth models. This method can be implemented using a computer program or run on a von Neumann-based device for filling undercuts in tooth models. The computer program can be integrated into an application or run as a standalone tool application. Specifically, it includes:

[0052] S101: Determine whether there is any tooth position movement among adjacent teeth in the three-dimensional tooth model, and obtain a determination result.

[0053] Specifically, a three-dimensional model is a polygonal representation of an object, which is usually displayed by a computer or other video equipment. In the embodiment of the present application, the three-dimensional tooth model is a polygonal representation of a person's complete teeth. The three-dimensional tooth model is obtained by scanning the teeth with a dental three-dimensional scanner. This is a prior art and will not be described in detail. It can be seen that the three-dimensional tooth model can clearly reflect the position and posture information of each tooth. Then, the position and posture information of each tooth in the three-dimensional tooth model is compared with the preset position and posture of the target tooth. If they are consistent, the judgment result is that the tooth position of the adjacent teeth has not moved; if they are inconsistent, the judgment result is that the tooth position of the adjacent teeth has moved.

[0054] S102: Determine the mesial control point and the distal control point between adjacent teeth according to the judgment result.

[0055] Specifically, in the embodiment of the present application, the mesial control point is the control point close to the midline, and the distal control point is the control point far from the midline. The midline is an imaginary vertical line that divides the craniofacial area into two equal parts, and distinguishes the mesial and distal parts of the teeth. Figure 2 As shown in the figure, when the result is that the adjacent teeth have not moved, the position indicated by A in the figure is determined as the mesial control point and distal control point on the adjacent teeth; when the result is that the adjacent teeth have moved, the position indicated by B in the figure is determined as the mesial control point and distal control point on the adjacent teeth. This can better describe the shape of the undercut between the adjacent teeth.

[0056] S103: Generate a corresponding undercut model according to the mesial control point and the distal control point.

[0057] Specifically, after determining the mesial and distal control points, two closed curves are first generated from the mesial and distal control points, respectively. The mesial and distal control points can control the shapes of the closed curves. Theoretically, at least three points are required to define a closed curve from points. Therefore, in the embodiment of the present application, at least three mesial and distal control points are required, respectively. Next, the surface is determined from the line, and the two closed curves are applied to the surface using a ruled surface generation algorithm. Finally, the volume is determined from the surface, and the surface is closed to obtain a model of the undercut between adjacent teeth, thereby determining the shape and size of the undercut between adjacent teeth.

[0058] S104: Fill the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance.

[0059] Specifically, after the undercut model between adjacent teeth is determined, the undercut model is filled into the undercut corresponding to the three-dimensional tooth model. There are two situations in the filling process. The first situation is that there is no overlapping area between the undercut model and the undercut area of ​​the three-dimensional tooth model. In this case, the undercut model can be filled into the undercut to obtain the target tooth model. The second situation is that there is an overlapping area between the undercut model and the undercut area of ​​the three-dimensional tooth model. In this case, the overlapping area on the undercut model is removed, and finally the target tooth model is filled. It should be noted that after obtaining the target tooth model, the target tooth model is 3D printed to obtain the actual target tooth model, and finally, the target tooth model is pressed and formed according to the actual target tooth model to produce a matching dental appliance.

[0060] See also Figure 3 The present application discloses a flowchart of another method for filling undercuts in tooth models. This method can be implemented using a computer program or run on a von Neumann-based device for filling undercuts in tooth models. The computer program can be integrated into an application or run as a standalone tool application. Specifically, it includes:

[0061] S201: Obtain a three-dimensional tooth model.

[0062] Specifically, a dental 3D scanner can be used to scan a person's teeth to obtain 3D data of the person's teeth, and then a 3D dental model can be created based on the 3D dental data. In other embodiments, a 3shape oral scanner can also be used to scan the teeth to obtain a 3D dental model.

[0063] S202: The three-dimensional tooth model includes initial tooth posture information, and the initial tooth posture information is calculated with preset target tooth posture information to obtain the rotation amount and translation amount of the tooth;

[0064] Specifically, the initial tooth pose information is the initial position and posture information of the tooth, and the preset target tooth pose information is the reasonable position and posture information of the tooth designed by the designer. The pose matrix T of the target tooth pose information relative to the initial tooth pose information is mainly composed of the rotation matrix R and the translation vector t, which is expressed as follows:

[0065] The translation vector t can be directly obtained by the coordinate difference between the coordinates of the specified point on the tooth in the target position and the initial state. In the embodiment of the present application, the rotation matrix R is described by Euler angles. Euler angles can decompose a rotation into three rotations around different coordinate axes in a certain order. The three rotation angles are α, β, and γ (where γ represents the axis inclination angle, α represents the torque angle, and β represents the torsion angle). The rotation matrix R can be represented by R y (α), R x (β) and R z (γ) The three matrices are decomposed to obtain:

[0066] R(α, β, γ) = R y (α)R x (β)R z (γ);

[0067]

[0068] Therefore, the multiplication of the three can be obtained to express the rotation matrix R:

[0069]

[0070] Finally, the pose matrix T is decomposed to obtain the rotation and translation of the tooth.

[0071] S203: If the rotation amount and the translation amount are both zero, the result is that the tooth position of the adjacent teeth has not moved; S204: If the rotation amount and the translation amount are not both zero, the result is that the tooth position of the adjacent teeth has moved.

[0072] Specifically, if both the rotation and translation values ​​are 0, it indicates that the tooth has not undergone angular deflection or positional shift, and the judgment result is that there is no tooth position shift between adjacent teeth. If the rotation and translation values ​​are not both 0, for example, the rotation value is 8 degrees and the translation value is 0, it indicates that the tooth has undergone an 8-degree angular shift, but has not shifted in position, and the judgment result is that there is tooth position shift between adjacent teeth. For another example, if the rotation value is 0 and the translation value is 4, it indicates that there is no angular shift, but has shifted in position by 4, and the judgment result is still that there is tooth position shift between adjacent teeth.

[0073] S205: When the judgment result is that the tooth position of adjacent teeth has moved, the first mesial control point between the adjacent teeth is selected, and the first mesial control point includes the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point.

[0074] S206: Selecting a first distal control point symmetrical to the first mesial control point, and using the first mesial control point as the mesial control point and the first distal control point as the distal control point.

[0075] Specifically, if there is a tooth position shift between adjacent teeth, four mesial points on the adjacent teeth are selected as mesial control points. In other embodiments, six or eight mesial control points may also be selected. Figure 4 As shown in the figure, the four points are the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point, and the first gingival lingual point. The first mandibular buccal point is located at the buccal 1 / 3 of the mesial marginal ridge, that is, the position of the mesial marginal ridge close to the buccal one-third of the tooth; the first mandibular lingual point is located at the lingual 1 / 3 of the mesial marginal ridge, that is, the position of the mesial marginal ridge close to the lingual one-third of the tooth; the first gingival buccal point is located at the projection of the first mandibular buccal point along the long axis of the tooth to the gingiva, and the first gingival lingual point is located at the projection of the first mandibular lingual point along the long axis of the tooth to the gingiva.

[0076] After the four mesial control points, namely the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point, are determined, the distal control point is then determined. The specific determination method is: four symmetrical points, namely the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point, are respectively taken as the distal control points. By selecting in this way, the flared gaps between adjacent teeth are not filled with undercuts, thereby increasing the contact area between the braces and the teeth and preventing the braces from falling off. Among them, the flared gaps are V-shaped gaps that expand outwards around the contact area of ​​the two teeth.

[0077] S207: When the result of the judgment is that there is no tooth position movement of the adjacent teeth, the second mesial control point between the adjacent teeth is selected, and the second mesial control point includes the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point and the second gingival lingual point.

[0078] S208: Selecting a second distal control point symmetrical to the second mesial control point, and using the second mesial control point as the mesial control point and the second distal control point as the distal control point.

[0079] Specifically, such as Figure 4 As shown in the figure, if there is no tooth movement in the adjacent teeth, four mesial control points on the adjacent teeth are selected as the mesial control points: the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point, and the second gingival lingual point. The second mandibular buccal point is located at the intersection of the mesial buccal cusp extending from the mesial proximal surface to the proximal surface, the second mandibular lingual point is located at the intersection of the mesial lingual cusp extending from the mesial proximal surface to the proximal surface, the second gingival buccal point is located at the mesial third of the midpoint of the buccal cervical margin line, and the second gingival lingual point is located at the mesial third of the midpoint of the lingual cervical margin line.

[0080] After determining the four mesial control points (second mandibular buccal point, second mandibular lingual point, second gingival buccal point, and second gingival lingual point), the distal control point is determined by selecting four symmetrical points, namely the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point, and the second gingival lingual point. This selection method allows the undercuts between adjacent teeth to be filled, facilitating the dislocation of the orthodontic appliance.

[0081] S209: Generate a mesial closed curve according to the mesial control point.

[0082] In a feasible implementation, in one embodiment, the proximal control point is used to generate a proximal closed curve using a cubic B-spline curve interpolation algorithm.

[0083] S210: Generate a mesial closed curve according to the mesial control point.

[0084] In a feasible implementation, in one embodiment, the distal control point is interpolated using a cubic B-spline curve interpolation algorithm to generate a distal closed curve.

[0085] Specifically, the interpolation values ​​involved in the cubic B-spline interpolation algorithm are known position points. The essence of the cubic B-spline interpolation algorithm is to find a B-spline curve that passes through all the position points. Among them, the B-spline curve refers to a special representation in the numerical analysis sub-discipline of mathematics. The specific B-spline curve is represented as: ∑N i,p P i , and through all position points F i ,Right now:

[0086]

[0087] The parameterization is expressed as R(u)=F i Where P is the control point sequence, N is the basis function value corresponding to the node of the curve. u is the node vector, F i is a known location point.

[0088] In the embodiment of the present application, the known position points are the mesial control point and the distal control point. The cubic B-spline curve interpolation algorithm is essentially to find the mesial closed curve and the distal closed curve passing through the position points.

[0089] Specifically, the near closed curve is expressed parameterized as R a (u i )=F i1 , the distal closed curve is expressed by parameter R b (u i )=F i2 . F i1 is the known near-center control point, F i2 is a known distal control point.

[0090] Because the algorithm uses a cubic B-spline curve, the order of the mesial closed curve and the distal closed curve is p = 3, and the node sequence can be derived to determine N i,p Then, by finding the control point P, we can get the parameterized expressions of the mesial closed curve and the distal closed curve respectively.

[0091] Now the number of node vectors m = x + 1 + 2 * p = x + 7. According to the relationship between the number of control points n, the order p, and the number of node vectors m, n = mp-1, the number of control points n = x + 7 - 4 = x + 3. In other words, x + 3 equations are needed to solve x + 3 unknowns. The current number of equations is x + 1. By adding two more equations by adding boundary conditions, we can obtain the parameterized expressions R for the mesial closed curve and the distal closed curve. a and R b .

[0092] S211: Based on the ruled surface generation algorithm, an undercut surface is generated through the mesial closed curve and the distal closed curve, and the undercut surface is closed to obtain a corresponding undercut model.

[0093] Specifically, in the embodiment of the present application, the ruled surface generation algorithm is expressed as: r(u,v)=R a (u)(1-v)+vR b (u), 0≤u,v≤1;

[0094] Among them, u and v represent two directions respectively, u is the direction of the curve, and v is between the two curves. Figure 5 The present application discloses a schematic structural diagram of an undercut model, wherein the mesial closed curve R obtained in step S210 is a and distal closed curve R b , are input into the algorithm respectively, and then the mesial closed curve R can be generated a and distal closed curve R b The surface r(u,v) in the v direction is finally sealed on the mesial and distal sides of the surface r(u,v) to obtain an undercut model for filling the undercut between adjacent teeth.

[0095] S212: Fill the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance.

[0096] For details, please refer to step S104 and will not be described in detail here.

[0097] The implementation principle of a method for producing an undercut filling in a tooth model according to an embodiment of the present application is as follows: after a three-dimensional tooth scanner acquires a three-dimensional tooth model, it determines whether the target position and posture of the teeth in the three-dimensional tooth model have changed relative to their initial position and posture. If so, a determination result is obtained that the tooth position of the adjacent teeth has moved; if not, a determination result is obtained that the tooth position of the adjacent teeth has not moved. Then, based on the determination results, the mesial control point and distal control point between the adjacent teeth are determined, a mesial closed curve is determined based on the mesial control point, and a distal closed curve is determined based on the distal control point. Finally, an undercut model is generated using the mesial closed curve and the distal closed curve. The undercut model is then filled into the undercut of the three-dimensional tooth model to obtain the target tooth model.

[0098] The following are device embodiments of the present application, which can be used to implement the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0099] See Figure 6 , a schematic diagram of the structure of a device for filling undercuts in tooth models provided in an embodiment of the present application. This device for filling undercuts in tooth models can be implemented as all or part of a device using software, hardware, or a combination of both. The device 1 includes a tooth movement determination module 11, a control point determination module 12, an undercut model generation module 13, and an undercut filling module 14.

[0100] The tooth movement judgment module 11 is used to judge whether there is a tooth position movement of adjacent teeth in the three-dimensional tooth model and obtain a judgment result;

[0101] The control point determination module 12 is used to determine the mesial control point and the distal control point between adjacent teeth according to the judgment result; the undercut model generation module 13 is used to generate the corresponding undercut model according to the mesial control point and the distal control point;

[0102] The undercut filling module 14 is used to fill the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance.

[0103] Optional, such as Figure 6 As shown, the control point determination module 12 is specifically configured to:

[0104] When the judgment result is that the tooth position of adjacent teeth has moved, the first mesial control point between the adjacent teeth is selected. The first mesial control point includes at least one, and the first mesial control point includes the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point. The first mandibular buccal point is located at the buccal 1 / 3 of the mesial marginal ridge, the first mandibular lingual point is located at the lingual 1 / 3 of the mesial marginal ridge, the first gingival buccal point is located at the projection of the first mandibular buccal point along the long axis of the tooth to the gingiva, and the first gingival lingual point is located at the projection of the first mandibular lingual point along the long axis of the tooth to the gingiva; the first distal control point symmetrical to the first mesial control point is selected, and the first mesial control point is used as the mesial control point, and the first distal control point is used as the distal control point.

[0105] Optional, such as Figure 6 As shown, the control point determination module 12 is further configured to:

[0106] When the result of the judgment is that there is no tooth position movement of the adjacent teeth, the second mesial control point between the adjacent teeth is selected, and the second mesial control point includes at least one, and the second mesial control point includes a second mandibular buccal point, a second mandibular lingual point, a second gingival buccal point and a second gingival lingual point. The second mandibular buccal point is located at the intersection of the mesial buccal cusp extending toward the mesial proximal surface and the proximal surface, the second mandibular lingual point is located at the intersection of the mesial lingual cusp extending toward the mesial proximal surface and the proximal surface, the second gingival buccal point is located at the mesial 1 / 3 of the midpoint of the buccal cervical margin line, and the second gingival lingual point is located at the mesial 1 / 3 of the midpoint of the buccal cervical margin line;

[0107] A second distal control point symmetrical to the second mesial control point is selected, and the second mesial control point is used as the mesial control point, and the second distal control point is used as the distal control point.

[0108] Optional, such as Figure 6 As shown, the undercut model generating module 13 is specifically used for:

[0109] Generate a mesial closed curve according to the mesial control point;

[0110] Generate a distal closed curve according to the distal control point;

[0111] Based on the ruled surface generation algorithm, an undercut surface is generated through the mesial closed curve and the distal closed curve. The undercut surface is closed to obtain the corresponding undercut model.

[0112] Optional, such as Figure 6 As shown, the undercut model generating module 13 is further used for:

[0113] The mesial control point is used to generate a mesial closed curve through the cubic B-spline curve interpolation algorithm;

[0114] Generate a distal closed curve based on the distal control points, including:

[0115] The distal control points are interpolated using the cubic B-spline curve algorithm to generate a distal closed curve.

[0116] Optional, such as Figure 6 As shown, the tooth movement judgment module 11 is specifically used for:

[0117] The initial tooth position information is calculated with the preset target tooth position information to obtain the rotation and translation of the tooth; if the rotation and translation are both zero, it is determined that there is no tooth position movement between adjacent teeth;

[0118] If the rotation amount and the translation amount are not all zero, the judgment result is that the tooth position of the adjacent teeth is moved.

[0119] Optional, such as Figure 7 As shown, the device 1 further includes:

[0120] The tooth model acquisition module 15 is used to acquire a three-dimensional tooth model.

[0121] It should be noted that the above-mentioned embodiment of a device for filling undercuts in a tooth model is provided only as an example of the division of the above-mentioned functional modules when performing a method for filling undercuts in a tooth model. In actual application, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the above-mentioned embodiment of a device for filling undercuts in a tooth model and the embodiment of a method for filling undercuts in a tooth model are based on the same concept. The implementation process is detailed in the method embodiment and will not be repeated here.

[0122] An embodiment of the present application further discloses a computer-readable storage medium, and the computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, a method for producing undercut filling in a tooth model according to the above embodiment is adopted.

[0123] Among them, the computer program can be stored in a computer-readable medium, the computer program includes computer program code, the computer program code can be in the form of source code, object code, executable file or certain middleware, etc. The computer-readable medium includes any entity or device that can carry computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that computer-readable medium includes but is not limited to the above-mentioned components.

[0124] Among them, through this computer-readable storage medium, a method for producing undercut filling of a tooth model in the above embodiment is stored in a computer-readable storage medium, and is loaded and executed on a processor to facilitate the storage and application of the above method.

[0125] An embodiment of the present application further discloses an electronic device, wherein a computer program is stored in a computer-readable storage medium. When the computer program is loaded and executed by a processor, the above-mentioned method for producing undercut filling in a tooth model is adopted.

[0126] Among them, the electronic device can be an electronic device such as a desktop computer, a laptop computer or a cloud server, and the electronic device includes but is not limited to a processor and a memory. For example, the electronic device can also include input and output devices, network access devices and buses, etc.

[0127] Among them, the processor can adopt a central processing unit (CPU). Of course, according to actual usage, other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be adopted. The general-purpose processor can adopt a microprocessor or any conventional processor, etc., and this application does not impose any restrictions on this.

[0128] Among them, the memory can be an internal storage unit of the electronic device, such as the hard disk or memory of the electronic device, or it can be an external storage device of the electronic device, such as a plug-in hard disk, smart memory card (SMC), secure digital card (SD) or flash memory card (FC) equipped on the electronic device. In addition, the memory can also be a combination of an internal storage unit and an external storage device of the electronic device. The memory is used to store computer programs and other programs and data required by the electronic device. The memory can also be used to temporarily store data that has been output or is to be output. This application does not impose any restrictions on this.

[0129] Among them, through this electronic device, the above-mentioned method for producing and filling the undercut of a tooth model is stored in the memory of the electronic device, and is loaded and executed on the processor of the electronic device for easy use.

[0130] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A method for filling undercuts in a tooth model, characterized in that: The method comprises: Determine whether there is a tooth position shift among adjacent teeth in the three-dimensional tooth model and obtain a determination result; Determining a mesial control point and a distal control point between adjacent teeth according to the judgment result; Generating a corresponding undercut model according to the mesial control point and the distal control point includes: generating a mesial closed curve according to the mesial control point; generating a distal closed curve according to the distal control point; Based on a ruled surface generation algorithm, an undercut surface is generated through the mesial closed curve and the distal closed curve, and the undercut surface is closed to obtain a corresponding undercut model; The undercut model is filled into the undercut of the three-dimensional tooth model to obtain a target tooth model for making an orthodontic appliance.

2. The method for filling undercuts in a tooth model according to claim 1, wherein: Determining the mesial control point and the distal control point of the adjacent teeth according to the judgment result includes: When the result of the judgment is that the tooth position of the adjacent teeth has moved, the first mesial control point between the adjacent teeth is selected, and the first mesial control point includes the first mandibular buccal point, the first mandibular lingual point, the first gingival buccal point and the first gingival lingual point, the first mandibular buccal point is located at the buccal 1 / 3 of the mesial marginal ridge, the first mandibular lingual point is located at the lingual 1 / 3 of the mesial marginal ridge, the first gingival buccal point is located at the projection of the first mandibular buccal point along the long axis of the tooth to the gingiva, and the first gingival lingual point is located at the projection of the first mandibular lingual point along the long axis of the tooth to the gingiva; A first distal control point symmetrical to the first mesial control point is selected, and the first mesial control point is used as the mesial control point, and the first distal control point is used as the distal control point.

3. The method for filling undercuts in a tooth model according to claim 1, wherein: Determining the mesial control point and the distal control point of the adjacent teeth according to the judgment result includes: When the judgment result is that there is no tooth position movement of the adjacent teeth, the second mesial control point between the adjacent teeth is selected, and the second mesial control point includes the second mandibular buccal point, the second mandibular lingual point, the second gingival buccal point and the second gingival lingual point. The second mandibular buccal point is located at the intersection of the mesial buccal cusp extending toward the mesial proximal surface and the proximal surface, the second mandibular lingual point is located at the intersection of the mesial lingual cusp extending toward the mesial proximal surface and the proximal surface, the second gingival buccal point is located at the mesial 1 / 3 of the midpoint of the buccal cervical margin line, and the second gingival lingual point is located at the mesial 1 / 3 of the midpoint of the lingual cervical margin line; A second distal control point symmetrical to the second mesial control point is selected, and the second mesial control point is used as the mesial control point, and the second distal control point is used as the distal control point.

4. The method for filling undercuts in a tooth model according to claim 1, wherein: Generating a mesial closed curve according to the mesial control point includes: The mesial control point is used to generate a mesial closed curve through a cubic B-spline curve interpolation algorithm; and a distal closed curve is generated according to the second distal control point; Generating a distal closed curve according to the distal control point includes: The distal control point is interpolated using a cubic B-spline curve algorithm to generate a distal closed curve.

5. The method for filling undercuts in a tooth model according to claim 1, wherein: The three-dimensional tooth model includes initial tooth position information, and the step of determining whether adjacent teeth in the three-dimensional tooth model have moved tooth positions to obtain a determination result includes: Calculating the initial tooth posture information and the preset tooth target posture information to obtain the rotation amount and translation amount of the tooth; If the rotation amount and the translation amount are both zero, it is determined that there is no tooth position movement of the adjacent teeth; If the rotation amount and the translation amount are not both zero, the judgment result is that the tooth position of the adjacent teeth is moved.

6. The method for filling undercuts in a tooth model according to claim 1, wherein: Before determining whether adjacent teeth in the three-dimensional tooth model have moved tooth positions, the method further includes: Obtain a 3D tooth model.

7. A device for filling undercuts in a tooth model, used to implement the method for filling undercuts in a tooth model according to any one of claims 1 to 6, characterized in that: include: A tooth movement judgment module (11) is used to judge whether there is a tooth position of adjacent teeth moved in the three-dimensional tooth model and obtain a judgment result; A control point determination module (12) is used to determine the mesial control point and the distal control point between adjacent teeth according to the judgment result; An undercut model generating module (13) is used to generate a corresponding undercut model according to the mesial control point and the distal control point; An undercut filling module (14) is used to fill the undercut model into the undercut of the three-dimensional tooth model to obtain a target tooth model for manufacturing an orthodontic appliance.

8. A computer-readable storage medium storing a computer program, wherein: When the computer program is loaded and executed by a processor, the method according to any one of claims 1 to 6 is adopted.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor loads and executes the computer program, the method according to any one of claims 1 to 6 is adopted.

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